Buggy code:
public class JMSPublisherGui extends AbstractSamplerGui implements ChangeListener { private static final long serialVersionUID = 240L ; private static final String ALL_FILES = "*.*" ; public static final String USE_FILE_RSC = "jms_use_file" ; public static final String USE_RANDOM_RSC = "jms_use_random_file" ; private static final String USE_TEXT_RSC = "jms_use_text" ; public static final String TEXT_MSG_RSC = "jms_text_message" ; public static final String MAP_MSG_RSC = "jms_map_message" ; public static final String OBJECT_MSG_RSC = "jms_object_message" ; private static final String [ ] CONFIG_ITEMS = new String [ ] { JMSPublisherGui . USE_FILE_RSC , JMSPublisherGui . USE_RANDOM_RSC , JMSPublisherGui . USE_TEXT_RSC } ; private static final String [ ] MSGTYPES_ITEMS = new String [ ] { JMSPublisherGui . TEXT_MSG_RSC , JMSPublisherGui . MAP_MSG_RSC , JMSPublisherGui . OBJECT_MSG_RSC } ; private final JCheckBox useProperties = new JCheckBox ( JMeterUtils . getResString ( "jms_use_properties_file" ) , false ) ; private final JLabeledRadioI18N configChoice = new JLabeledRadioI18N ( "jms_config" , JMSPublisherGui . CONFIG_ITEMS , JMSPublisherGui . USE_TEXT_RSC ) ; private final JLabeledTextField jndiICF = new JLabeledTextField ( JMeterUtils . getResString ( "jms_initial_context_factory" ) ) ; private final JLabeledTextField urlField = new JLabeledTextField ( JMeterUtils . getResString ( "jms_provider_url" ) ) ; private final JLabeledTextField jndiConnFac = new JLabeledTextField ( JMeterUtils . getResString ( "jms_connection_factory" ) ) ; private final JLabeledTextField jmsDestination = new JLabeledTextField ( JMeterUtils . getResString ( "jms_topic" ) ) ; private final JCheckBox useAuth = new JCheckBox ( JMeterUtils . getResString ( "jms_use_auth" ) , false ) ; private final JLabeledTextField jmsUser = new JLabeledTextField ( JMeterUtils . getResString ( "jms_user" ) ) ; private final JLabeledTextField jmsPwd = new JLabeledTextField ( JMeterUtils . getResString ( "jms_pwd" ) ) ; private final JLabeledTextField iterations = new JLabeledTextField ( JMeterUtils . getResString ( "jms_itertions" ) ) ; private final FilePanel messageFile = new FilePanel ( JMeterUtils . getResString ( "jms_file" ) , JMSPublisherGui . ALL_FILES ) ; private final FilePanel randomFile = new FilePanel ( JMeterUtils . getResString ( "jms_random_file" ) , JMSPublisherGui . ALL_FILES ) ; private final JLabeledTextArea textMessage = new JLabeledTextArea ( JMeterUtils . getResString ( "jms_text_message" ) ) ; private final JLabeledRadioI18N msgChoice = new JLabeledRadioI18N ( "jms_message_type" , JMSPublisherGui . MSGTYPES_ITEMS , JMSPublisherGui . TEXT_MSG_RSC ) ; public JMSPublisherGui ( ) { } public String getLabelResource ( ) { } public TestElement createTestElement ( ) { } public void modifyTestElement ( TestElement s ) { } private void init ( ) { } @ Override public void clearGui ( ) { super . clearGui ( ) ; useProperties . setSelected ( false ) ; jndiICF . setText ( "" ) ; urlField . setText ( "" ) ; jndiConnFac . setText ( "" ) ; jmsDestination . setText ( "" ) ; jmsUser . setText ( "" ) ; jmsPwd . setText ( "" ) ; textMessage . setText ( "" ) ; messageFile . setFilename ( "" ) ; randomFile . setFilename ( "" ) ; msgChoice . setText ( "" ) ; configChoice . setText ( JMSPublisherGui . USE_TEXT_RSC ) ; updateConfig ( JMSPublisherGui . USE_TEXT_RSC ) ; <START_BUG> iterations . setText ( "" ) ; <END_BUG> useAuth . setSelected ( false ) ; } @ Override public void configure ( TestElement el ) { } public void stateChanged ( ChangeEvent event ) { } private void updateConfig ( String command ) { } private void updateMessageType ( String msgType ) { } }

Fix:
iterations . setText ( "1" ) ;